[PATCH v5 6/6] hwmon: pwm-fan: Code for using PWM FAN as a cooling device

2015-02-25 Thread Lukasz Majewski 
The PWM FAN device can now be used as a thermal cooling device. Necessary
infrastructure has been added in this commit.

Signed-off-by: Lukasz Majewski l.majew...@samsung.com
---
Changes for v2:
- Replace pwm_fan_cooling_states with pwm_fan_cooling_levels
- Update ctx-pwm_fan_state when correct data from device tree is available
- Using therma_cdev_update() when thermal is ready for controlling the fan
Changes for v3:
- Rename patch heading
- pwm_fan_of_get_cooling_data() now returns -EINVAL when no cooling-levels
  property defined
- register of cooling device only when proper cooling data is present
Changes for v4:
- None
Changes for v5:
- Check for IS_ENABLED(CONFIG_THERMAL) has been added to prevent from
  executing thermal_* specific functions
---
 drivers/hwmon/pwm-fan.c | 83 -
 1 file changed, 82 insertions(+), 1 deletion(-)

diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
index e6ed353..2c1a8f0 100644
--- a/drivers/hwmon/pwm-fan.c
+++ b/drivers/hwmon/pwm-fan.c
@@ -24,6 +24,7 @@
 #include linux/platform_device.h
 #include linux/pwm.h
 #include linux/sysfs.h
+#include linux/thermal.h
 
 #define MAX_PWM 255
 
@@ -68,6 +69,17 @@ exit_set_pwm_err:
return ret;
 }
 
+static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
+{
+   int i;
+
+   for (i = 0; i  ctx-pwm_fan_max_state; ++i)
+   if (pwm  ctx-pwm_fan_cooling_levels[i + 1])
+   break;
+
+   ctx-pwm_fan_state = i;
+}
+
 static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
   const char *buf, size_t count)
 {
@@ -82,6 +94,7 @@ static ssize_t set_pwm(struct device *dev, struct 
device_attribute *attr,
if (ret)
return ret;
 
+   pwm_fan_update_state(ctx, pwm);
return count;
 }
 
@@ -103,6 +116,59 @@ static struct attribute *pwm_fan_attrs[] = {
 
 ATTRIBUTE_GROUPS(pwm_fan);
 
+/* thermal cooling device callbacks */
+static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
+unsigned long *state)
+{
+   struct pwm_fan_ctx *ctx = cdev-devdata;
+
+   *state = ctx-pwm_fan_max_state;
+
+   return 0;
+}
+
+static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
+unsigned long *state)
+{
+   struct pwm_fan_ctx *ctx = cdev-devdata;
+
+   if (!ctx)
+   return -EINVAL;
+
+   *state = ctx-pwm_fan_state;
+
+   return 0;
+}
+
+static int
+pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long state)
+{
+   struct pwm_fan_ctx *ctx = cdev-devdata;
+   int ret;
+
+   if (!ctx || (state  ctx-pwm_fan_max_state))
+   return -EINVAL;
+
+   if (state == ctx-pwm_fan_state)
+   return 0;
+
+   ret = __set_pwm(ctx, ctx-pwm_fan_cooling_levels[state]);
+   if (ret) {
+   dev_err(cdev-device, Cannot set pwm!\n);
+   return ret;
+   }
+
+   ctx-pwm_fan_state = state;
+
+   return ret;
+}
+
+static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
+   .get_max_state = pwm_fan_get_max_state,
+   .get_cur_state = pwm_fan_get_cur_state,
+   .set_cur_state = pwm_fan_set_cur_state,
+};
+
 int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
 {
struct device_node *np = dev-of_node;
@@ -145,8 +211,9 @@ int pwm_fan_of_get_cooling_data(struct device *dev, struct 
pwm_fan_ctx *ctx)
 
 static int pwm_fan_probe(struct platform_device *pdev)
 {
-   struct device *hwmon;
+   struct thermal_cooling_device *cdev;
struct pwm_fan_ctx *ctx;
+   struct device *hwmon;
int duty_cycle;
int ret;
 
@@ -193,6 +260,20 @@ static int pwm_fan_probe(struct platform_device *pdev)
if (ret)
return ret;
 
+   ctx-pwm_fan_state = ctx-pwm_fan_max_state;
+   if (IS_ENABLED(CONFIG_THERMAL)) {
+   cdev = thermal_of_cooling_device_register(pdev-dev.of_node,
+ pwm-fan, ctx,
+ pwm_fan_cooling_ops);
+   if (IS_ERR(cdev)) {
+   dev_err(pdev-dev,
+   Failed to register pwm-fan as cooling device);
+   pwm_disable(ctx-pwm);
+   return PTR_ERR(cdev);
+   }
+   thermal_cdev_update(cdev);
+   }
+
return 0;
 }
 
-- 
2.0.0.rc2

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Re: [PATCH v5 6/6] hwmon: pwm-fan: Code for using PWM FAN as a cooling device

2015-02-25 Thread Eduardo Valentin 
Hey Lukasz,

On Wed, Feb 25, 2015 at 04:34:22PM +0100, Lukasz Majewski wrote:
 The PWM FAN device can now be used as a thermal cooling device. Necessary
 infrastructure has been added in this commit.
 
 Signed-off-by: Lukasz Majewski l.majew...@samsung.com
 ---
 Changes for v2:
 - Replace pwm_fan_cooling_states with pwm_fan_cooling_levels
 - Update ctx-pwm_fan_state when correct data from device tree is available
 - Using therma_cdev_update() when thermal is ready for controlling the fan
 Changes for v3:
 - Rename patch heading
 - pwm_fan_of_get_cooling_data() now returns -EINVAL when no cooling-levels
   property defined
 - register of cooling device only when proper cooling data is present
 Changes for v4:
 - None
 Changes for v5:
 - Check for IS_ENABLED(CONFIG_THERMAL) has been added to prevent from
   executing thermal_* specific functions
 ---
  drivers/hwmon/pwm-fan.c | 83 
 -
  1 file changed, 82 insertions(+), 1 deletion(-)
 
 diff --git a/drivers/hwmon/pwm-fan.c b/drivers/hwmon/pwm-fan.c
 index e6ed353..2c1a8f0 100644
 --- a/drivers/hwmon/pwm-fan.c
 +++ b/drivers/hwmon/pwm-fan.c
 @@ -24,6 +24,7 @@
  #include linux/platform_device.h
  #include linux/pwm.h
  #include linux/sysfs.h
 +#include linux/thermal.h
  
  #define MAX_PWM 255
  
 @@ -68,6 +69,17 @@ exit_set_pwm_err:
   return ret;
  }
  
 +static void pwm_fan_update_state(struct pwm_fan_ctx *ctx, unsigned long pwm)
 +{
 + int i;
 +
 + for (i = 0; i  ctx-pwm_fan_max_state; ++i)
 + if (pwm  ctx-pwm_fan_cooling_levels[i + 1])
 + break;
 +
 + ctx-pwm_fan_state = i;
 +}
 +
  static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
  const char *buf, size_t count)
  {
 @@ -82,6 +94,7 @@ static ssize_t set_pwm(struct device *dev, struct 
 device_attribute *attr,
   if (ret)
   return ret;
  
 + pwm_fan_update_state(ctx, pwm);
   return count;
  }
  
 @@ -103,6 +116,59 @@ static struct attribute *pwm_fan_attrs[] = {
  
  ATTRIBUTE_GROUPS(pwm_fan);
  
 +/* thermal cooling device callbacks */
 +static int pwm_fan_get_max_state(struct thermal_cooling_device *cdev,
 +  unsigned long *state)
 +{
 + struct pwm_fan_ctx *ctx = cdev-devdata;
 +

Why this call back is the only one you didn't add a check for ctx ==
NULL?

 + *state = ctx-pwm_fan_max_state;
 +
 + return 0;
 +}
 +
 +static int pwm_fan_get_cur_state(struct thermal_cooling_device *cdev,
 +  unsigned long *state)
 +{
 + struct pwm_fan_ctx *ctx = cdev-devdata;
 +
 + if (!ctx)
 + return -EINVAL;
 +
 + *state = ctx-pwm_fan_state;
 +
 + return 0;
 +}
 +
 +static int
 +pwm_fan_set_cur_state(struct thermal_cooling_device *cdev, unsigned long 
 state)
 +{
 + struct pwm_fan_ctx *ctx = cdev-devdata;
 + int ret;
 +
 + if (!ctx || (state  ctx-pwm_fan_max_state))
 + return -EINVAL;
 +
 + if (state == ctx-pwm_fan_state)
 + return 0;
 +
 + ret = __set_pwm(ctx, ctx-pwm_fan_cooling_levels[state]);
 + if (ret) {
 + dev_err(cdev-device, Cannot set pwm!\n);
 + return ret;
 + }
 +
 + ctx-pwm_fan_state = state;
 +
 + return ret;
 +}
 +
 +static const struct thermal_cooling_device_ops pwm_fan_cooling_ops = {
 + .get_max_state = pwm_fan_get_max_state,
 + .get_cur_state = pwm_fan_get_cur_state,
 + .set_cur_state = pwm_fan_set_cur_state,
 +};
 +
  int pwm_fan_of_get_cooling_data(struct device *dev, struct pwm_fan_ctx *ctx)
  {
   struct device_node *np = dev-of_node;
 @@ -145,8 +211,9 @@ int pwm_fan_of_get_cooling_data(struct device *dev, 
 struct pwm_fan_ctx *ctx)
  
  static int pwm_fan_probe(struct platform_device *pdev)
  {
 - struct device *hwmon;
 + struct thermal_cooling_device *cdev;
   struct pwm_fan_ctx *ctx;
 + struct device *hwmon;
   int duty_cycle;
   int ret;
  
 @@ -193,6 +260,20 @@ static int pwm_fan_probe(struct platform_device *pdev)
   if (ret)
   return ret;
  
 + ctx-pwm_fan_state = ctx-pwm_fan_max_state;
 + if (IS_ENABLED(CONFIG_THERMAL)) {
 + cdev = thermal_of_cooling_device_register(pdev-dev.of_node,
 +   pwm-fan, ctx,
 +   pwm_fan_cooling_ops);


I know this is a PITA, but thermal subsystem still does not use devm
based helpers. That means, you need to be old school and unregister the
device yourself.

Please add the cdev to ctx structure:
+   ctx-cdev = cdev;

and add a call for:
thermal_cooling_device_unregister(ctx-cdev);

in static int pwm_fan_remove(struct platform_device *pdev)


despite the above two minor issues, you may add my
Acked-by: Eduardo Valentin edubez...@gmail.com

 + if (IS_ERR(cdev)) {
 + dev_err(pdev-dev,
 +